Yarn inspection apparatus



Feb. 5, 1963 H. BARBER 3,076,251

YARN INSPECTION APPARATUS Filed July 29, 1960 INV E NTOR HerberZ Barber BY Wadi fim a.

TTORNEY 3,076,251 YARN INSPECTION APPARATUS Herbert Barber, Pensacola, Fla., assignor, by mesne assignments, to Monsanto Chemical Company, a corporation of Delaware Filed July 29, 1960, Ser. No. 46,288

8 Claims. (Cl. 28-64) The present invention relates to yarn inspection appara tus and more particularly to yarn inspection apparatus permitting the passage of transfer knots therethrough.

Generally, in the inspection of yarn, such as in the warping of tricot yarn, it is desirable to have 100 percent inspection of the yarn with respect to broken filaments, slubs, loops, snarls or any other type of physical defects producing a change in the yarn diameter. complete inspection of yarn it is quite desirable to allow the passage of transfer or tie-in knots beyond the yarn inspection apparatus to thereby prevent snagging of the knot and possible breakage of the yarn in the apparatus. A transfer or tie-in knot is the knot made when a tail end of yarn on one bobbin is tied to the supply end of yarn on another bobbin.

It is well known that knots formed in the yarn should not be introduced, for example, into a constant tension yarn feeding mechanism or into a slub detection device,

in order to eliminate the snagging or breakage of the yarnin going through these devices. However, present methods of preventing knots from contacting yarn processing apparatus in a manner to cause yarn breakage are substantially of the type where the knotted yarn is manually brought through the apparatus before processing the yarn through such devices, such as in a warping operation. In other types of yarn fabricating apparatus, after a knot has been formed an appreciable amount of slack is provided therein so that by the time that the loop is drawn after knotting, the knot would have passed the portion of the apparatus which would have caused snagging or breaking of the yarn.

Consequently, it would appear that presently used means for preventing the passage of transfer or tie-in knots through such apparatus as a yarn tensioning and slub snagging devices are either semiautomatically or manually operative. These techniques 'do not permit economical and mass production inspection of yarn, and introduce a high degree of human error in such inspections. Accordingly,.it would be desirable in a complete mechanical inspection of yarn to reduce the number of manual steps and eliminate possible human error by having a com pletely automatic yarn inspection apparatus.

The present invention in its preferred form comprises an automatic means of raising the yarn out of a cleaner or slub detector when a transfer or tie-in knot indicator approaches the cleaner. The yarn is raised by a solenoidoperated guide, the solenoid being temporarily energized when the yarn supply shifts from one bobbin to another. In this manner, a device is disclosed which offers complete inspection of the yarn while allowing the passage of transfer knots through the inspection apparatus, thereby eliminating yarn snagging or breakage which would otherwise be caused by the tie-in knot.

An object of this invention is to provide a novel and improved device for inspecting yarn. Another-object of this invention is to provide a yarn inspection device which will snag and break the yarn when a slub or the like appears but which will allow the passage of tie-in knots.

A further object of the present invention is the provision of a yarn inspector which will detect broken filaments, slubs, and the like, which may produce a change in the yarn diameter, and which'inspector will still allow the passage of transfer or tie-in knots.

Hence, for

United States Patent 9 n 3,076,251 Patented Feb. 5, 1963 Still another object of this invention is to provide a yarn inspection device which automatically separates the moving yarn from the inspection device in response to the approach of a knot.

Other objects and advantages of this invention will become apparent as the following detailed description is read in conjunction with the accompanying drawing, in which:

The single FIGURE is a schematic view of a preferred embodiment of the invention showing the general arrangement of the various elements.

Referring now to the drawing, there is illustrated a preferred embodiment of a yarn inspection apparatus comprising a standby bobbin 11 supplied with a yarn 12 having a head or leading end tied to the transfer tail or end of a yarn 13 on a supply bobbin 16 by a transfer or tie-in knot 17. This is a well-known arrangement. The bobbins 11 and 16 are supported on a base, fragments of which are shown supporting the various elements of the apparatus and which are designated 18A, 18B, 18C, and 18D.

The yarn from the supply bobbin 16 is passed through a tension device 20 of a well-known type and to a cleaner device 21 mounted on the base fragment 18B and, in turn, through an eyelet of a swing arm 22 which may be pivoted to raise the yarn out of the cleaner device 21.

The full stand-by bobbin 11 is provided to supplement the supply bobbin 16 whenever it becomes depleted. In this transfer operation, the yarn from the stand-by bobbin is tied, either automatically or by manual means, to the end of the yarn 13 on the supply bobbin 16 by the transfer or tie-in knot 17. Consequently, in the flow of yarn from such a device as a frame holding a supply of yarn bobbins to the yarn processing or fabricating machine, it is desirable to prevent the knot 17 from snagging or breaking the yarn in its passage through the cleaner device 21.

The invention, as illustrated by the preferred embodiment, prevents the transfer knot 17 from coming into contact with the cleaner device 21, in response to a signal from a transfer indicator 24 to thereby prevent snagging or breaking of the yarn and maintain a continuous transfer of yarn'from the creel.

The transfer indicator 24 is provided with a movable contact bar 25 pivotally mounted at one end on a pin 27 attached to the base and adapted to be moved by the yarn into contact with a curved bar 26 attached to the base. The yarn leading from the standby bobbin 11 to the supply bobbin 16 is manually positioned behind the movable contact bar 25 to pivot this bar into engagement with the curved bar 26 when the yarn supply shifts from the bobbin 16 to the standby bobbin 11. The contact bar 25 and the curved bar 26 form a switch which detects the shifting of the yarn feed from the bobbin 16 to the bobbin 11.

The tension device 20 provided between the bobbin 16 and the cleaner device 21 may be any conventional design, such as a multiple flexible finger or a pulley and friction type. In the pulley type, the yarn is wound about a tension pulley which is retarded by a suitable braking device, such 'as a friction drag pulley, or the like. However, for the purposes of the present invention the tension. device is only schematically shown since the operation of the invention is independent of the particular tension means utilized. At any rate, the tension device 20 maintains a predetermined tension on the yarn advanced from the creel to the particular machine or device the yarn is transmitted to.

therethrough, In the present invention, the cleaner device is provided with a pair of cleaner blades 28 vertically mounted on a platform 29 secured to the base fragment 18B and provided with a guide pin 32 to provide a straight feeding path for the yarn through the cleaner blades. The cleaner blades are formed with a trumpeted or flared opening 33 therebetween so that the yarn cleaning operation will be performed only in the lower or narrow portion of the opening. The lower or narrow portion of the opening 33 is of such a width that any slubs or other such defects in the yarn will be caught and will cause the yarn to break. The upper portion of the opening 33 is such a width that the knot 17 will pas-s therethrough.

Yarn moving means, such as the swing arm 22, is provided adjacent the exit end of the cleaner blades 28, and is provided with a yarn eyelet 34, through which the yarn passes. The swing arm 22 is pivotally mounted on a pin 37 attached to the base. The are of the swing arm is predeterminedly adjusted so that the eyelet 34 in its lowermost position directs the yarn between the narrow portion in the trumpeted or flared opening 33 between the cleaner blades 28 and above the cleaner blades in its high position as shown in the drawing. A tension spring 40 is secured to the swing arm 22 and the base fragment 18D to bias and normally maintain the swing arm in its lowermost position and to return the arm to this position after it has been actuated to its high position.

A solenoid 42 is connected to the swing arm 22 through a link 43 which physically connects the end of the swing arm with the solenoid 42. The other end of the solenoid is suitably connected to a dashpot 45 of a well-knewn type attached to the armature of the solenoid to predeterminedly set the speed at which the swing arm 22 returns to its lowermost position. A battery 44 connected to the solenoid 42 and the transfer indicator 24 serves to energize the solenoid when the shifting of the yarn feed from the bobbin 16 to the bobbin 11 moves the contact bar 25 into engagement with the curved bar 26, thereby elevating the swing arm 22 and raising the yarn out of the narrow portion and into the wide portion of the opening 33.

In the operation of the preferred embodiment of the present invention, the yarn 13 leaves the supply bobbin 16 and passes through the tensioning device 20 and, in turn, between the cleaner blades 28 and through the eyelet 34 for complete yarn inspection. Defects in the yarn are caught in the lower or narrow portion of the trumpeted or flared opening 33 between the cleaner blades 28, which either removes any loose matter on the yarn or causes a break in the yarn if any non-removable physical defects are present which changes the cross-sectional area of the yarn beyond a predetermined limit.

After a break in the yarn, the absence of tension in the yarn is noted by a suitable stop motion means of a wellknown type (not shown) inherent in the tension'device 20, which causes the cessation of the operation to allow an operator to remedy the defect by removal thereof and to tie the yarn for continuation of the operation. Generally, the absence of tension in the yarn actuates an electric contact in the tension device 20 which, for example, flashes a suitable signal for the operator, such as a light, or the like, and also causes stoppage of the apparatus.

After the yarn on the supply bobbin 16 is substantially exhausted, the yarn 12 from the standby bobbin 11 is tied by a transfer or tie-in knot 17 to the end of the supply bobbin yarn 13 by suitable automatic or manual means for continuation of the inspection.

When the yarn on the bobbin 16 is exhausted, the yarn will feed from the standby bobbin 11, the yarn path then being directly from the bobbin 11 to the tension device 20. When the yarn path shifts or transfers from the bobbin 16 to the bobbin 11, the yarn adjacent to the knot 17 will pivot the contact bar 25 into engagement with the curved bar 26. This completes the circuit to the solenoid 42, which pivots the arm 22 to lift the yarn out of the flared opening 33 before the knot reaches the cleaner device.

The preferred embodiment is predeterminedly designed so that operation of the transfer indicator 24 by the shifting of the yarn path will energize the solenoid 42 and actuate the attached swing arm 22 when the knot is approaching the cleaner blades 28. If desired, the dashpot 45 may be predeterminedly varied in a well-known manner to prevent the return of the arm 22 to its lowermost position for any desired period of time to permit the transfer knot 17 to travel from any point in its path of travel to the region beyond the cleaner blades 28. Hence, the spring 40 attached to the swing arm 22, in cooperation with the dashpot 45, will gradually return the swing arm 22 and its integral eyelet 34 to the position shown in the drawing so that the yarn again passes between the lower portions of the cleaner blades after the knot 17 has cleared these blades. It will be obvious that the yarn should be removed from the cleaner blades only long enough to ermit the movement of the transfer knot 17 beyond the cleaner blades so that the cleaner blades may again be operative in inspecting the yarn for any physical defects.

It should be understood, of course, that the foregoing disclosure relates to only a preferred embodiment of the invention and that it is intended to cover all changes and modifications of the example of the invention herein chosen for the purposes of the disclosure, which do not constitute departures from the spirit and scope of the invention as set forth in the appended claims.

What is claimed is:

1. A yarn inspection apparatus adapted to detect physical defects in a yarn which produce a change in the yarn diameter, comprising cleaner means having an opening for the yarn to move through along a path of travel, means adjacent to said cleaner means for displacing the path of travel of the yarn out of said opening, means in the path of travel of the yarn at a position in advance of said cleaner means for detecting the transfer of yarn feed from one bobbin to another, and means actuated by the detecting means for operating said displacing means.

2. In a yarn inspection apparatus having yarn supplying means, detecting means for sensing a transfer of the yarn feed path from one part of the supply means to another, cleaner means operatively associated with said detecting means for removing any physical defects producing a change in the yarn diameter, and movable means actuated by said detecting means for predeterminedly removing the yarn from said cleaner means to prevent the passing of knots therethrough.

3. A device for inspecting yarn, comprising a cleaner having an opening through which yarn to be inspected is adapted to pass along a path of travel, means adjacent to the cleaner for displacing the yarn laterally to its path of travel out of the opening in the cleaner, means engaging the yarn for sensing a span of yarn extending from one bobbin to another and having a knot therein, said sensing means being positioned so as to sense said span before the knot reaches the cleaner, and means interconnected between the sensing means and the displacing means and actuated by the knot sensing means for operating the displacing means.

4. A device for inspecting yarn, comprising a cleaner having an opening through which the yarn is adapted to pass, said opening having a narrow portion and a wide portion, a member movably positioned adjacent to the opening and having an aperture through which the yarn passes, said aperture normally being positioned in alignment with the narrow portion of the opening, means adjacent to the cleaner for sensing a change in the yarn feed path from one bobbin to another, means connected to the movably positioned member for moving said memher to align the aperture therein with the wide portion of the opening, and means interconnecting the sensing means and the movably positioned member for actuating said member when said span is sensed.

5. A device for inspecting yarn, comprising a slub detector having an opening through which yarn to be inspected is adapted to pass, a member movably mounted adjacent to the slub detector and having an aperture through which the yarn passes, a switch positioned adjacent to the slub detector in engagement with the yarn in such a manner that a change in the yarn feed path from one bobbin to another closes the switch, and means interconnecting the switch and the movably mounted member for moving said member to displace the yarn out of said opening when said change closes the switch.

6. A device for inspecting yarn, comprising a base, a slub detector mounted on the base and having an opening through which the yarn is adapted to be passed, an arm pivotally mounted on the base and having an aperture through which the yarn passes, said aperture normally being aligned with the opening in the slub detector for directing the yarn therethrough, a switch positioned adjacent to the yarn and adapted to be closed in response to a transfer in the yarn feed from one bobbin to another, a solenoid connected to the switch, a battery connected to the solenoid for energizing the solenoid when the switch is closed, and a link interconnecting the solenoid and the arm for pivoting the arm to move the yarn out of the opening when the switch is closed in response to said transfer.

7. A device for inspecting yarn, comprising a base, a slub detector mounted on the base and having an opening through which a yarn is to pass, an arm movably mounted on the base and having an opening through which the yarn passes, said arm being movable to move the yarn path into or out of the opening in the slub detector, means for moving the arm to move the yarn path out of the opening in the slub detector, and sensing means actuated by a shift of the yarn feed from one bobbin to another for actuating the arm moving means.

8. A device for inspecting yarn, comprising a base, a slub detector mounted on the base and having an opening for the passage of a yarn, an arm movably mounted on the base and having an opening through which the yarn passes, said arm being movable to shift the yarn path into or out of the opening in the slub detector, a solenoid connected to the arm for moving said arm to shift the path of the yarn out of the opening in the slub detector, means attached to the arm for urging said arm toward an operative poistion to shift the yarn path into the opening in the slub detector, a dashpot connected to the solenoid for delaying the return of the arm to the operative position thereof, and means actuated by a shift of the yarn feed from one bobbin to another for energizing the solenoid to move the arm.

References Cited in the file of this patent UNITED STATES PATENTS 2,844,861 Strange et a1. July 29', 1958 

1. A YARN INSPECTION APPARATUS ADAPTED TO DETECT PHYSICAL DEFECTS IN A YARN WHICH PRODUCE A CHANGE IN THE YARN DIAMETER, COMPRISING CLEANER MEANS HAVING AN OPENING FOR THE YARN TO MOVE THROUGH ALONG A PATH OF TRAVEL, MEANS ADJACENT TO SAID CLEANER MEANS FOR DISPLACING THE PATH OF TRAVEL OF THE YARN OUT OF SAID OPENING, MEANS IN THE PATH OF TRAVEL OF THE YARN AT A POSITION IN ADVANCE OF SAID CLEANER MEANS FOR DETECTING THE TRANSFER OF YARN FEED FROM ONE BOBBIN TO ANOTHER, AND MEANS ACTUATED BY THE DETECTING MEANS FOR OPERATING SAID DISPLACING MEANS. 